1. Field of the Invention
The present invention relates to digital television receivers and more particularly to a method of performing a time-shift function in a television receiver.
2. Discussion of the Related Art
A television receiver provided with a personal video recorder includes a storage medium such as a hard disc drive for recording (storing) and reproducing video signals including their associated audio components. The stored signals are digital video signals that are input to the television receiver and may be broadcast signals received from a broadcast station or other signals such as those supplied from a peripheral device connected to the television receiver. In any case, the input signals are encoded for storage in a transport stream format.
For instance, a television broadcast receiver provided with a personal video recorder (PVR) may employ a hard disc drive as a storage medium to enable a received broadcast signal or an external input signal from an external player to be stored in and reproduced from the hard disc according to a time-shift function in response to a user selection input. Such a time-shift function enables playback functions of pause, reverse play, fast or slow play, and the like for displaying a real-time broadcast signal or other, similarly received, video stream.
A contemporary television receiver provided with a PVR receives a broadcast signal in real time, stores the received broadcast signal in a time-shift storage area of the PVR's storage medium, and displays a time-shift guide using on screen display (OSD) data superposed on the displayed (viewed) video signal of the broadcast signal. The time-shift guide includes a progress bar for indicating a quantity of data storage, i.e., a storage status of the broadcast signal in the time-shift storage area, and for enabling a user control of a selective playback of the stored broadcast signal to be selected for playback. The storage status of a broadcast signal is typically displayed using a cache bar, and a movable indicator is provided for designating a specific point along the progress bar, the specific point corresponding to the currently viewed broadcast signal, which is then read out from the storage medium from the corresponding point.
When executing a time-shift function in a contemporary television receiver provided with a PVR, the television receiver stores a received real-time broadcast signal in a time-shift storage area of a storage medium and uses on-screen display (OSD) data to display a time shift guide generated in correspondence with the broadcast program stored in the time-shift storage area. The time shift guide includes a progress bar that indicates a storage status of a broadcast program. If a user designates a specific point of the progress bar, the television receiver displays (reproduces) the stored broadcast program from the designated point. Namely, the television receiver is able to store a currently viewed broadcast program in real time and play back the stored contents. Therefore, a broadcast program received via a switched channel according to a user's channel switching or a changed broadcast program, e.g., a change made in accordance with the programming schedule of a broadcast station, is sequentially stored in real time within the time-shift storage area; the time-shift function, however, merely tracks (follows) a storing status of a single broadcast program, as a contiguous (uninterrupted) transport stream.
Therefore, a user has difficulty in identifying a desired playback position for a specific program and in recognizing other identifying information for a specific program, such that accurately performing the desired playback operation may be rendered impossible or otherwise impractical, particularly when there is a large number of broadcast signals stored in the hard disc. Moreover, the time shift guide as described above indicates a program's storage status only and thus can provide no identifying information for a stored broadcast program, for example, program title or detailed storage time. As a result, it is difficult to select a specific broadcast program for playback, since there is no identifying information made available to the user.